GB1319684A - Hoists - Google Patents
HoistsInfo
- Publication number
- GB1319684A GB1319684A GB3028270A GB3028270A GB1319684A GB 1319684 A GB1319684 A GB 1319684A GB 3028270 A GB3028270 A GB 3028270A GB 3028270 A GB3028270 A GB 3028270A GB 1319684 A GB1319684 A GB 1319684A
- Authority
- GB
- United Kingdom
- Prior art keywords
- motor
- brake
- voltage
- potentiometer
- comparator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
- B66C13/00—Other constructional features or details
- B66C13/18—Control systems or devices
- B66C13/22—Control systems or devices for electric drives
- B66C13/23—Circuits for controlling the lowering of the load
- B66C13/26—Circuits for controlling the lowering of the load by ac motors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
- B66C2700/00—Cranes
- B66C2700/08—Electrical assemblies or electrical control devices for cranes, winches, capstans or electrical hoists
- B66C2700/081—Electrical assemblies or electrical control devices for cranes, winches, capstans or electrical hoists with ac motors
Landscapes
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Mechanical Engineering (AREA)
- Stopping Of Electric Motors (AREA)
Abstract
1319684 Automatic speed control RICHIER 22 June 1970 [ 20 June 1969] 30282/70 Heading G3R A hoist is driven by an asynchronous motor 2 which is coupled to an eddy-current brake 3. A tachometer 6 responds to the speed of the motor and sends a signal to comparator 7 which also receives a reference signal from potentiometer 8. The error signal from the comparator is applied to a thyristor circuit 9 for controlling the motor voltage and to a rectifier circuit 10 which determines the voltage applied to the brake, and thus the braking torque. The torque changes rapidly with speed at low speeds to ensure stable operation, particularly with small loads. In this manner, the load is raised and lowered at set speeds. A current detector 15 is connected to a voltage regulator 16 which prevents sudden changes in the motor voltage when the potentiometer 8 is adjusted abruptly. In a modification, the brake is formed by an auxiliary stator winding arranged concentrically with the main stator winding of the motor. For lowering light loads, the auxiliary winding may have a smaller number of poles than the main winding, which provides the braking component.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR6919877A FR2045183A5 (en) | 1969-06-20 | 1969-06-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1319684A true GB1319684A (en) | 1973-06-06 |
Family
ID=9035762
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3028270A Expired GB1319684A (en) | 1969-06-20 | 1970-06-22 | Hoists |
Country Status (2)
Country | Link |
---|---|
FR (1) | FR2045183A5 (en) |
GB (1) | GB1319684A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3876918A (en) * | 1972-08-14 | 1975-04-08 | Hitachi Ltd | Electric motor controlling system |
-
1969
- 1969-06-20 FR FR6919877A patent/FR2045183A5/fr not_active Expired
-
1970
- 1970-06-22 GB GB3028270A patent/GB1319684A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
FR2045183A5 (en) | 1971-02-26 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |